I have a 2007 2WD PreRunner AC that has served me well for on-road driving, but I'm looking at trading it in for a new 2010 4WD TRD OR DC.

While 90% of my driving is on road, I do a lot of outdoor activities that take me onto dirt which turns into mud in the rain. Plus, my brother is an avid off roader/rock crawler who tries to get me to off road my Tacoma with his rebuilt Jeep. Haven't taken him up on it yet because mine's 2WD with an open differential.

Also, while the Access Cab fits my needs now (and it's halfway paid off), the Double Cab looks a lot better for kids which my wife and I plan to have in a couple years.

I kind of regretted the 2WD purchase as soon as I made it, and I don't want to make that mistake again. If I end up trading mine in, I plan to keep the new truck until it dies.

Anyway, the new Tacomas offers a lot of features over my 07. On the off road side, the auto-LSD looks pretty effective, especially when coupled with 4WD (the front wheels have the auto-LSD too right?), and the rear locker on the TRD OR is attractive. As for the interior, the compass/temp gauge, backup camera, stereo aux input, etc offer a lot over the relatively basic 07.

I've been to two dealerships and neither had any 4WD models with the TRD OR package. Apparently that's not a very common configuration in Texas, so it looks like I'm going to have to pay a pretty penny for it as they would barely budge on the price at all. However, there is one more dealership in town that has a couple, so maybe they can play ball. Used 4WD TRD OR models are also extremely rare in my area. The closest ones were several hours away.

There are several non-TRD 4WDs in the area, and I wonder if the auto-LSD negates the usefulness of the OR's locking differential. I guess I could always add a rear locker to the PreRunner later if I feel the need (but then I'd lose the upgraded suspension).

I figure my options are to go all out on the TRD OR, save some money and buy the 4WD PreRunner, or save a lot of money and keep my 07 and install an ARB rear locker for my off road needs.

I appreciate any suggestions.

I have no clue what the new Tacoma's options are. I do see new one's they are SR5' with crap wheels and so on.
You got that right, crap wheels are the norm. Check this out. If your going tacoma DC SR5 sport. 3" lift wheels-tires. I like the sport, you get the fake hood intake (I can make work) & no chrome. I think they are all auto's no 6 spd. (not sure about that). My self I dont need room i'd get a reg cab short bed and lift it to the sky. Or just go for the Trunda and lift that.

on the off roading side of the conversation, I will say that I have a PreRunner and have done a good amount of offroading and only gotten stuck. Frankly, you aren't going to want to take a TRD OR places your relative goes in his jeep. It'll be brand new and you aren't going to want to scratch it up and what not.... Sure theres been trails that I would only go up if I had 4wd, but I wouldn't be going up them anyway... I'd buy a trail rig to do that stuff... Don't get me wrong, I love off roading and use my truck, just saying that my LSD is all I need. ( Gotta use good technique tho = don't slow down in some parts )

I also know that I would rarely use the 4x4.. so kinda pointless there..

but I think having a d-cab for kids is a must! So theres your excuse to go get a new Taco. That being said, go for a 4x4 if you're buying one new.